The present invention relates generally to object management and storage systems and more particularly to integrated techniques for the creation and management of multiple versions and context variants of objects within larger collections of related objects as well as techniques for dynamic resolution of links between the objects and accurate version retrieval based on specified criteria.
An object management system can be defined as a system used to manage objects which are to be accessed, viewed, or edited in a multi-user environment. An object, in this context, can be defined as any file which is created, edited, or viewed by a user. Objects include file formats such as text, graphics, binary, audio, etc. A first user creates the original file, and subsequently, multiple users view or edit the file. In the past, it has been difficult to manage large numbers of documents that are simultaneously being edited by various users and always retrieve the most accurate or recent version of the document. If two users have the right to edit the same document and both transfer the document to their front end editing applications, work on it simultaneously, and then transfer different versions of the document back into the storage system, one of the users will overwrite the changes of the other. The present invention utilizes versioning processes and a check-in/-out mechanism to prevent this scenario from arising.
Furthermore, in the past new versions of documents usually create problems for sources that refer to them. A source document contains a reference, or link, to a target document. When a source refers to a particular target, and the target has been modified in a newer version of the target, the source would ideally now refer to the newest version of the target. The reference somehow has to be changed to point to the new version. If there are multiple references to the older version of the document, all references must be modified. The links do not necessarily have to be in source documents in the traditional sense, but can also be in any type of object, particularly business objects.
This problem is evident in hypertext documents in document publishing on the World Wide Web. Documents on the Web are written in Hypertext Markup Language. It is common for a hypertext document to contain links, known as hyperlinks, to other hypertext documents. When the source hypertext document contains a hyperlink to a target hypertext document, that hyperlink has to be modified if a new version of the target hypertext document has been created. If the target hypertext document has been moved to another location in the storage system, the hyperlink must again be modified.
This problem has been resolved in the past by simply allowing the new version of the target document to assume the identity of the original target document, such that the references would not have to be changed. However, this approach has problems. For example, if a French source document refers to an English target document before a French version of the target document became available, when a French version does become available, it simply cannot be allowed to overwrite the English version of the target document because there may be other English source documents that are referring to the English version of the target document.
It is desirable to be able to create new version of documents while maintaining the original version. Often, the modification or editing of a version of a document is not necessarily a correction, implying an overwrite of the original document. For example, new versions may simply be changes in terms of format, language, etc.
The invention relates to a computer system for managing and storing objects comprising a storage mechanism such as a database, an optical archive, a Web-based document server, a management agent, an administration data table, and a client front-end editor/browser application. Objects are defined as any type of file or document in any format. Examples of objects are text, binary files, graphics, etc. The invention manages objects having various versions by using a three-tiered content model.
The model consists of components, physical objects, and logical objects. Multiple physical objects belong to one logical object, while the physical object itself represents an individual document. The logical object is the upper most tier, describing the object in its most generic terms. The logical object is also referred to as a collection. Any number of physical objects, i.e. objects which are meta-descriptions of the different binary objects that actually exist at any time, may belong to a logical object. A physical object describes a particular version that belongs to exactly one logical object which represents the general meaning of the subject matter described. The physical object contains references to the components, which contain the administration data associated with the files and pointers to said files.
The system provides a control mechanism to prevent the simultaneous editing of an object by multiple users. The check-in/-out mechanism allows the object management system to maintain data accuracy in a large, multi-user environment. When an object has been checked out, the management agent will set up a lock for the original physical object within the administration data table that will prevent other users from accessing the object with the intent of changing it or transferring a new version into the Knowledge Provider. When a first user has checked out a document and a second user tries to check out the same document, the management agent will consult the check-out information and refuse the request.
The system also comprises a context resolution mechanism which, upon request for a logical object, allows for the retrieval of the most appropriate physical object associated with that logical object on the basis of the context, the correlation between the user""s current language, format, etc. The context resolution is performed on the basis of the attributes of the physical objects encapsulated by a particular logical object as well as the attributes of the user""s client application. In addition, the process of context sensitive selection can be augmented by application specific rules and information. Each physical object associated with a particular object has different attributes, i.e. language, format, etc. Context resolution compares the attributes of each physical object with the attributes of the user""s front-end client application.
The system further comprises a logical hyperlink mechanism which provides for references between various objects in the system. In a preferred embodiment, a Web-based document server is the storage mechanism and various objects are referenced via hyperlinks. This mechanism uses xe2x80x9csoftxe2x80x9d or logical hyperlinks which allow context-depending selection of target documents at run-time and do not refer to a specific object at a specific location. The logical hyperlink references a Global Unique Identifier (GUID) of the logical object and the identifier of the executable program. The attributes required to select the proper physical object are not generated until runtime. In this way, the logical hyperlink is in essence a type of xe2x80x9clate bindingxe2x80x9d which shields the client application from the back-end mechanisms which are being implemented. When a source object references a target object, and a newer version of the target object has been created, the logical hyperlink mechanism will dynamically reference the newest version of the target object.
The storage and management system is integrated with various client applications through business application programming interfaces (BAPI""s). The client applications can retrieve physical objects from the system by sending requests which are returned by the system back to the client application.
The system provides for the integration of different types of content servers, allowing users and client applications to access information from a broad spectrum of servers. Additionally, search engines are integrated to avoid the formation of information islands.
It is an object of the present invention to provide a method for the management of objects such that different versions of the same object can be created and managed.
It is a further object of the invention to provide a mechanism for the versioning of objects.
It is a further object of the invention to construct relations between objects in the system based on different established criteria as well as user-defined criteria.
It is a further object of the invention to provide a management and storage system which can be integrated with a variety of front-end editor/browser applications.
It is a further object of the invention to provide a method for establishing and maintaining links and references between various objects while objects are being dynamically versioned.
It is a further object of the invention to provide for the accurate retrieval of particular versions of an object in response to a call from a front-end client application.
It is a further object of the invention to provide multiple users with access to the same objects without compromising the accuracy of the objects.
It is a further object of the invention to provide the integration of different types of content servers for an object management system.
It is a further object of the invention to provide application augmented context-sensitive selection of physical objects.
It is a further object of the invention to provide the integration of search engines for an object management system.